Diagnosis and management of delusional parasitosis

REVIEW

Diagnosis and management of delusional parasitosis Elliott H. Campbell, BSc,a Dirk M. Elston, MD,b James D. Hawthorne, MD,c and David R. Beckert, MDd Lexington, Kentucky, and Charleston, South Carolina Delusional parasitosis is a monosymptomatic hypochondriacal state that causes great suffering for the patient and great suffering for those around them. Dermatologists are experts in the diagnosis of cutaneous disease and frequently encounter such patients. This review provides an overview of the diagnosis and management of delusional parasitosis and the differential diagnosis. ( J Am Acad Dermatol https://doi.org/ 10.1016/j.jaad.2018.12.012.) Key words: chronic tactile hallucinosis; delusional parasitosis; delusions of parasitosis; delusory parasitosis; Ekbom syndrome; psychogenic parasitosis.

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elusional parasitosis (DP), also commonly referred to as delusions of parasitosis, delusional infestation, or Ekbom syndrome, is a monosymptomatic hypochondriacal psychosis in which affected individuals have a fixed, false belief that they are infested with living organisms. The German term Dermatozoenwahn (parasitosis) was originally cited in 1938 by Karl Axel Ekbom to describe this disorder. The name Ekbom syndrome was later used to describe this disorder; however, this eponym is ambiguous because it can also be used to refer to restless leg syndrome.1 Morgellons disease is a condition in which a patient perceives fibers or threads emerging from or attached to the skin. Many of these patients demonstrate fixed ideation of infestation that affects their work and relationshipsdmanifestations that are typical of delusional parasitosis.2,3 DP is a type of delusional disorder, somatic type (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition code 297.1 F22).4 Previous editions of the Diagnostic and Statistical Manual of Mental Disorders required individuals with this diagnosis to have nonbizarre delusions, which is no longer a requirement. Criteria include the presence of a delusion for $1 month where the criteria for schizophrenia have not been met, the patient is

functioning in general outside of the delusion of parasitosis, mood episodes have been brief relative to the duration of the delusional period(s), and where the disturbance is not attributable to medical conditions, substances, or another disorder.4 We summarize the current literature regarding epidemiology, diagnosis, and management in this review. Evidence-based recommendations for pharmacologic management and side effect profiles of the available agents are discussed in the context of the authors’ experience.

From the University of Kentucky College of Medicinea and the Department of Psychiatry,c University of Kentucky, Lexington, and the Departments of Dermatology and Dermatologic Surgeryb and Psychiatry,d Medical University of South Carolina, Charleston. Funding sources: None. Conflicts of interest: None disclosed.

Accepted for publication December 3, 2018. Reprint requests: Elliott H. Campbell, BSc, 2011 Madison Rd, Cincinnati, Ohio 45208. E-mail: [email protected]. Published online March 17, 2019. 0190-9622/$36.00 Ó 2018 by the American Academy of Dermatology, Inc. https://doi.org/10.1016/j.jaad.2018.12.012

METHODS The PubMed database was queried for relevant articles using the following search terms: delusional parasitosis OR delusions of parasitosis OR delusional infestation OR delusory parasitosis OR psychogenic parasitosis OR chronic tactile hallucinosis OR Ekbom syndrome (NOT restless leg). The search produced a total of 597 articles, 122 case reports, 22 case series, 58 reviews, 2 systematic reviews, 1 randomized controlled trial, and 1 metaanalysis. Articles were selected for review based on their relevance to the presentation, differential diagnosis, evaluation, and management of DP. Side effect profiles were extracted from the results of pharmaceutical trials included in the product labeling. Recommendations

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are based on the published literature and the authors’ experience in managing the disorder.

genuine parasitosis. Older patients with scabies often have atypical presentations, and burrows may not be evident. Some patients actually isolate individual scabies, zoonotic, or environmental mites, DISCUSSION and it pays to examine the specimens that the patient Presentation provides. Bites and infestations may produce cliniThe mean age of patients with DP is 57 years, cally nonspecific lesions, and obtaining a biopsy there is a roughly 3:1 female:male ratio, and females specimen can help rule out may have a longer duration genuine arthropod reactions. of symptoms compared with CAPSULE SUMMARY Wedge-shaped perivascular males.5 Past or comorbid polymorphous infiltrates psychiatric conditions are reDelusional parasitosis can be effectively often with eosinophils and ported in roughly 80% of managed with second-generation endothelial swelling are patients with DP.6,7 The antipsychotic agents. characteristic of the latter. most common comorbid Extrapyramidal and metabolic side Mites, both scabetic and psychiatric illness was effects are major limiting factors in the nonscabetic, are the most depression (74%), followed choice of therapy. common causes of cryptic by substance abuse (24%) arthropod-induced pruritus. and anxiety (20%).6 Patients Based on the published data on efficacy, They range in size from 0.1 are often highly distressed the incidence of side effects, and to 2 mm and may be difficult and the condition dominates attributable risk, risperidone (0.5-4 mg/ to see without magnificatheir lives, disrupting perday) is a reasonable first-line choice for tion. Many lack host specisonal and professional relapharmacotherapy. ficity, and avian mitetionships. Some remain induced dermatitis may tremendously successful at result from contact with either birds or rodents, work while their private lives are consumed by the including pet gerbils and hamsters. Mites are widely delusions. Many of the patients have read extendistributed in nature, and conditions such as ‘‘grosively about the parasites they believe infest them. cer’s itch’’ may be related to a wide variety of They typically bring ‘‘specimens’’ as proof of their agricultural products. Pet-induced dermatitis and infestation and may relate accounts of failed drastic natural fillings for pillows and mattresses have also measures to eradicate the infestation. The been associated with cryptic mite-induced derma‘‘matchbox sign’’ is the classic presentation of various toses. Caterpillars and moths often appear in great materials that have been collected by the patient as numbers, and their dislodged hairs can cause urtievidence of infestation, including anything from caria and pruritus. dust/dirt, plant or animal fibers, scabs and skin Formication and pruritus caused by medicadebris to photographs of old/previous lesions or tions, such as amphetamines (both illegal and parasites. One can often find real insects/arthropods prescription), dopamine agonists,9 opioids, topin the matchbox, but they are typically innocent iramate,10 cocaine,11 or alpha-adrenergic agents peridomestic organisms. Patients may describe an must also be considered. Pruritus related to sysexposure to a dirty environment or a sexual temic diseases, including hyperthyroidism and encounter that they believe to be the origin of the renal and liver disease, may present with generalinfestation. In some cases, they believe family ized itch or a crawling sensation in the skin. members are also affected and may expose them to
Exposure to fiberglass may produce itching of significant risk in their attempts to cure them. Folie a unknown etiology, and fiberglass-contaminated deux, a condition in which a psychiatric condition clothing placed in the laundry can result in itching (delusion or hallucination) is transferred from one in an entire family. individual to another, is not uncommon in this Other psychiatric disorders should also be considsetting.8 Patients experience formication, hallucinaered, including schizophrenia spectrum disorders, tory crawling sensations on the skin attributed to the dementia, affective psychoses, substance-induced presence of the alleged parasites. psychoses, and psychoses caused by a general medical condition (eg, iron deficiency anemia). Differential diagnosis Anxiety disorders, obsessive compulsive disorder, A thorough evaluation is required, including a and somatoform disorders should be carefully distincomplete history and physical examination. Table I guished from delusional states and may be comorbid lists some of the more common diseases on the with delusional disorder. differential diagnosis. It is important to rule out d

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Evaluation A complete blood cell count, metabolic panel, thyroid-stimulating hormone, obtaining a biopsy specimen of lesional skin, and perilesional skin for direct immunofluorescence may help to rule out organic disease and help to establish an effective physicianepatient relationship. Dermatologists can use adhesive tape, cyanoacrylate stripping of skin, and dermoscopy to detect evidence of mites. Patients and exterminators can examine the house and office for evidence of nesting birds or vermin. We have sometimes found it helpful to evaluate the vacuum cleaner bag contents (most forms of inanimate debris will sink, but mites will float on alcohol or hypertonic sugar solution). In the rare cases where mites are identified, an acarologist can comment on their relevance. A qualified veterinarian should examine pets. Specimens should be cleared with lactic acid or lactophenol, washed with water, and mounted in Hoyer medium, which remains clear regardless of whether mites are prepared with water or alcohol. Hoyer medium is typically prepared by the laboratory handling the specimen. Local and state health departments, university entomology departments, and military entomologists can be extremely helpful. In our experience, they have always been generous with their time and expertise. Many dermatologists are familiar with arthropods that are commonly associated with human disease, images of which are readily found in the dermatology literature. When necessary, an expert can be consulted. It is important to properly isolate and preserve arthropod specimens before submitting them. If substanceinduced psychosis is suspected, a urine drug screen is highly valuable as well as a search of controlled substances that are being prescribed via a database network search. Management Reassurance regarding the lack of evidence of organic disease rarely provides relief to the patient, and patients often see multiple physicians in search of someone who will believe them. It is important to establish a positive physicianepatient relationship and to emphasize the importance of global evaluation and management to address all aspects of the problem, including pharmacotherapy to alleviate symptoms. Direct confrontation with the patient regarding their delusions is rarely successfuldby definition, they are fixed and unchangeable. Some confrontation occurs in cognitive behavioral therapy approaches to delusional disorder, but this requires significant expertise and patients who are open to psychotherapy.

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Table I. Differential diagnosis of delusional parasitosis Scabies Avian mite-induced dermatitis Grocer’s itch Pet-induced dermatitis Caterpillar and moth dermatitis Fiber glass dermatitis Substance-induced (amphetamines, opioids, cocaine, etc) Pruritus related to systemic diseases Schizophrenia spectrum disorders Dementia Other psychiatric disorders

Patients will often ask questions, such as ‘‘Do you think I’m crazy?’’ Experienced physicians have differing strategies for how to reply to questions like these, and none are universally effective. Some patients respond to ‘‘I believe you are really suffering, and I would like to try to help you.’’ Others have responded with ‘‘I think we’re all a bit crazy at times. It’s okay. Let’s focus on your symptoms and getting you better.’’ Another approach is to answer with a question that is directed at the patient’s anxiety. For instance, ‘‘Has someone told you that you were crazy?’’ or ‘‘What would it mean if you were?’’ Topical antipruritic agents containing camphor and menthol or pramoxine may provide temporary relief of dysesthesias. A small, randomized controlled trial found that N-acetylcysteine has been shown to decrease skin-picking behavior in picking disorders.12 This drug is thought to modulate glutamate levels and may help with compulsive behavior, such as skin picking and trichotillomania; however, dermatology-specific outcomes (ie, the number of excoriations) has not been studied. This has not been studied in the setting of DP. If the patient demonstrates compulsive picking of suspected sites of the infestation, this may be a helpful pharmacotherapy with a low side effect profile. Antipsychotic agents are the most effective agents to treat DP, but many dermatologists are uncomfortable with the pharmacologic management of DP. One study found that only 3% of dermatologists were comfortable prescribing the required agents.13 Our objective in this section is to familiarize dermatologists with the efficacy and side effect profile of antipsychotics in treating DP. With this knowledge, it is our hope that dermatologists will feel more comfortable administering these medications to patients with DP. When appropriate drugs are

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Table II. Comparison of side effects of pharmacotherapy for delusional parasitosis Therapy

Suggested dose

Adult short-term side effects

Total event rate, %

Attributable risk, %

Pimozide

1-10 mg/day

Risperidone

0.5-4 mg/day

Aripiprazole

2-10 mg/day

Olanzapine

5-10 mg/day

Sedation Akinesia Akathisia Rigidity Visual disturbance Adverse behavioral event Total cholesterol (\200-$204) Triglycerides (\500-$500) Weight gain ($7% increase from baseline) Parkinsonism Akathisia Sedation Total cholesterol (\200-$240) Fasting triglycerides (\150-$200) Weight gain ($7% increase from baseline)* Extrapyramidal disorder Akathisia Sedation Total cholesterol (\200-$240) Fasting triglycerides (\150-$200) Weight gain ($7% increase from baseline)* Asthenia Akathisia Somnolence

70 40 40 10 20 25 4.3 2.7 8.7 14 10 10 2.5 7.4 5.2 5 10 7 2.8y 9.2z 40.6 10 3 29

45 40 40 10 20 25 1.6 1.6 5.8 6 7 8 0.3 0.4 3.6 2 6 3 0.4 4.8 30.8 1 1 16

*Data based on an adolescent patient population. All data were from the product insert of each drug.40-43 y After 48 weeks, 14.8% event rate. z After 48 weeks, 32.4% event rate (no placebo group).

Table III. Advantages and disadvantages of pharmacotherapy for delusional parasitosis Therapy

Advantages

Pimozide

Has the most published literature supporting its efficacy

Risperidone

Lower rate of EPS compared with pimozide; lower rate of metabolic effects compared with olanzapine; more literature supports its efficacy compared with other atypical antipsychotics Lower rate of EPS compared with pimozide; lower rate of metabolic effects compared with olanzapine; less risk of EPS and prolactinemia compared with risperidone Lower rate of EPS compared with pimozide

Aripriprazole

Olanzapine

Disadvantages

Recommendations

Second-line

High side effect profile (akathisia, akinesia, rigidity, and sedation) make this unfavorable Slightly higher risk of EPS compared with aripiprazole; higher risk of prolactinemia compared with other atypical antipsychotics

First-line*

Less literature that supports its efficacy compared with risperidone

Alternate first-line

Much higher rates of metabolic effects compared with other atypicals make this unfavorable

Second-line

EPS, Extrapyramidal symptoms. *Usual first-line recommendation.

prescribed, the clinical response rate to antipsychotics ranges from 50% to 100%.14-17 In the past, pimozide was used as the first-line agent, but it has a less favorable side effect profile

compared with second generation (atypical) antipsychotic agents, and electrocardiograms are recommended to measure the Q-T interval before treatment18 (Tables I-III). There is level 1B evidence

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Table IV. Major drug interactions of pharmacotherapy for delisional parasitosis Therapy

Pimozide

Risperidone Aripiprazole

Olanzapine

Major drug interactions40-43

Macrolide antibiotics Citalopram and escitalopram Sertraline CYP2D6 inhibitors CYP3A4 inhibitors CYP2D6 inducers CYP2D6 inhibitors Strong CYP3A4 inhibitors Strong CYP2D6 inhibitors Strong CYP3A4 inducers Antihypertensive drugs Benzodiazepines CYP1A2 inducers CYP2D6 inhibitors CYP1A2 inhibitors Alcohol Diazepam Antihypertensive agents

Potential effect

(CI) Prolonged QT intervals, may decrease metabolism (CYP3A4 inhibitor) (CI) Increases QTc by unknown mechanism (CI) Decrease clearance (CI) Decrease clearance of pimozide (CI) Decrease metabolism of pimozide Increase clearance of risperidone Decrease clearance of risperidone Decrease clearance of aripiprazole Decrease clearance of aripiprazole Increase clearance of aripiprazole Hypotension Orthostatic hypertension, sedation Increase clearance of olanzapine Decrease clearance of olanzapine Decrease clearance of olanzapine Orthostatic hypotension Orthostatic hypotension May potentiate hypotension

This is not an all encompassing list. A more comprehensive list can be found in the package insert of each medication. Inhibitors include quinidine, parozetine, and fluoxetine. CYP2D6 inducers include cabamazepine. CYP3A4 inhibitors include azole, macrolide, protease inhibitors, nefazodone, zileuton, and fluvoxamine. CYP3A4 inducers include cabamazepine and rifampin. CYP1A2 inhbitors include fluvoxamine. CYP1A2 inducers include carbamazepine. CI, Contraindicated; CYP, cytochrome P450.

for using pimozide, with 1 small randomized crossover trial, 5 case series, and several case reports.5,19-21 While pimozide is still used successfully to treat DP, we prefer newer atypical antipsychotic agents because of their favorable side effect profiles. Atypical antipsychotic medications other than pimozide do not require an electrocardiogram before beginning pharmacotherapy. As a rule, atypical antipsychotic medications require the periodic monitoring of laboratory values. We recommend that all patients who are receiving any medication in this class of drugs undergo a baseline lipid panel assessment and have their fasting glucose and Hgb A1c levels checked, then later rechecked after being on the medication for 3 months and then checked again after 1 year. It is also important to monitor the patient’s weight at these intervals. While electrocardiograms are not needed as part of routine care for patients who are taking risperidone, attention to possible drug interactions is important. Risperidone,22-24 olanzapine,19,25 aripiprazole,26-28 paliperidone,29 ziprasidone,30 and quetiapine31 have all been successfully used as monotherapy for DP. Serotonergic drugs have also been listed as effective in case reports.32,33 Of these, risperidone, aripiprazole, and olanzapine appear most frequently in the literature. These drugs and pimozide’s side effects,

advantages and disadvantages, and drug interactions are compared in Tables II to IV. Olanzapine has limited evidence to support its efficacy in DP.19,25 The evidence is limited to 1 systematic review, 2 case series (in which some of the patients were treated with olanzapine), and a few case reports. One systematic review found its efficacy to be 72%.15 Patients have responded to doses as low as 2.5 mg.25 The problem associated with olanzapine is its metabolic effects (Table II). We do not recommend olanzapine as first-line pharmacotherapy for DP, but if patients do not respond to atypical antipsychotic medications, olanzapine can be started at 5 mg per day and worked up to 10 mg per day. Patients should be monitored for the metabolic effects, including triglycerides and cholesterol. Although aripiprazole has the lowest side effect profile of the atypical antipsychotic medications, it also has the least amount of evidence, limited to 7 case reports. If patients are concerned about the weight gain associated with atypical antipsychotic medications, aripiprazole may be an alternative because it is not associated with increased weight gain. The literature to support risperidone comes from a systematic review, case series, and several case

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reports.15,17,22-24 Efficacy in the systematic review was found to be 69%.15 There are no randomized controlled trials. We recommend risperidone starting at 0.5 mg and working up to 4 mg because it has more evidence to support its efficacy than aripiprazole and fewer side effects than olanzapine. Tables II, III, and IV list the common side effects and drug interactions that should be reviewed before starting these medications. Patients are typically more receptive to prescription medications once the physicianepatient relationship has been established. In our experience, statements such as ‘‘This medication will help eliminate the crawling sensations that you are experiencing’’ or ‘‘I want to focus on managing your symptoms, and this medication will help’’ are effective. We often add that medications have many usesdfor example, ‘‘Doxepin is an antidepressant, but we commonly use it as an antihistamine. Other drugs used in psychiatry are also valuable to dermatologists.’’ The median onset of a clinical response after starting therapy is 1.5 weeks, with a maximum effect often achieved by 6 weeks.15 Discontinuation of therapy after clinical response commonly results in a relapse of symptoms.19 Side effects are a common cause of discontinuation of therapy. While serious side effects are uncommon in our experience, 1 randomized controlled trial found that 36.5% of patients with schizophrenia treated with an average of 3.8 mg of risperidone for 8 weeks experienced some extrapyramidal symptoms (EPSs), with an average dropout rate of 38.5% (average 50.8 days after starting therapy).34 EPSs resulting from risperidone therapy are dose-dependent.35 Antipsychotic medicationeinduced movement disorders occur more frequently in elderly patients.36 If EPS occurs after treatment, short-term treatment strategies include lowering the dose or using a different agent. Benztropine may be used for parkinsonism; however, this is not optimal for long-term management because of its side effects (tachycardia, problems with memory, and other anticholinergic effects).37 Akathisia may be treated with a short course of low-dose propranolol38 or a benzodiazepine. Psychotherapy alone has a reported efficacy of 10%; however, if the patient is amenable, psychotherapy in combination with pharmacologic therapy may be more helpful.39 Advice from an experienced psychiatrist is invaluable. They are experts in the use of psychoactive medications, but because many patients reject the idea of referral to a psychiatrist, the dermatologist also needs a working knowledge of the agents used to treat this challenging disorder.

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We hope that this review will help dermatologists provide more effective therapy for these patients. REFERENCES 1. Freudenmann RW, Lepping P. Delusional infestation. Clin Microbiol Rev. 2009;22:690-732. 2. Murase JE, Wu JJ, Koo J. Morgellons disease: a rapportenhancing term for delusions of parasitosis. J Am Acad Dermatol. 2006;55:913-914. 3. Pearson ML, Selby JV, Katz KA, et al. Clinical, epidemiologic, histopathologic and molecular features of an unexplained dermopathy. PLoS One. 2012;7:e29908. 4. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Washington, DC: American Psychiatric Association; 2013. 5. Boggild AK, Nicks BA, Yen L, et al. Delusional parasitosis: sixyear experience with 23 consecutive cases at an academic medical center. Int J Infect Dis. 2010;14:e317-e321. 6. Foster AA, Hylwa SA, Bury JE, Davis MD, Pittelkow MR, Bostwick JM. Delusional infestation: clinical presentation in 147 patients seen at Mayo Clinic. J Am Acad Dermatol. 2012;67: 673.e1-673.e10. 7. Hylwa SA, Foster AA, Bury JE, Davis MD, Pittelkow MR, Bostwick JM. Delusional infestation is typically comorbid with other psychiatric diagnoses: review of 54 patients receiving psychiatric evaluation at Mayo Clinic. Psychosomatics. 2012;53:258-265. 8. Giam A, Tung YL, Tibrewal P, Dhillon R, Bastiampillai T. Folie
a deux and delusional parasitosis. Asian J Psychiatry. 2017;28: 152-153. 9. Flann S, Shotbolt J, Kessel B, et al. Three cases of delusional parasitosis caused by dopamine agonists. Clin Exp Dermatol. 2010;35:740-742. 10. Fleury V, Wayte J, Kiley M. Topiramate-induced delusional parasitosis. J Clin Neurosci. 2008;15:597-599. 11. Brewer JD, Meves A, Bostwick JM, Hamacher KL, Pittelkow MR. Cocaine abuse: dermatologic manifestations and therapeutic approaches. J Am Acad Dermatol. 2008;59:483-487. 12. Grant JE, Chamberlain SR, Redden SA, Leppink EW, Odlaug BL, Kim SW. N-Acetylcysteine in the treatment of excoriation disorder: a randomized clinical trial. JAMA Psychiatry. 2016;73: 490-496. 13. Gee SN, Zakhary L, Keuthen N, Kroshinsky D, Kimball AB. A survey assessment of the recognition and treatment of psychocutaneous disorders in the outpatient dermatology setting: how prepared are we? J Am Acad Dermatol. 2013;68: 47-52. 14. Wong S, Bewley A. Patients with delusional infestation (delusional parasitosis) often require prolonged treatment as recurrence of symptoms after cessation of treatment is common: an observational study. Br J Dermatol. 2011;165:893-896. 15. Freudenmann RW, Lepping P. Second-generation antipsychotics in primary and secondary delusional parasitosis: outcome and efficacy. J Clin Psychopharmacol. 2008;28:500508. 16. Manschreck TC, Khan NL. Recent advances in the treatment of delusional disorder. Can J Psychiatry. 2006;51:114-119. 17. Lepping P, Russell I, Freudenmann RW. Antipsychotic treatment of primary delusional parasitosis: systematic review. Br J Psychiatry. 2007;191:198-205. 18. Mothi M, Sampson S. Pimozide for schizophrenia or related psychoses. Cochrane Database Syst Rev. 2013;11:CD001949. 19. Martins AC, Mendes CP, Nico MM. Delusional infestation: a case series from a university dermatology center in S~ao Paulo, Brazil. Int J Dermatol. 2016;55:864-868.

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20. Lindskov R, Baadsgaard O. Delusions of infestation treated with pimozide: a follow-up study. Acta Derm Venereol. 1985;65:267-270. 21. Hamann K, Avnstrop C. Delusions of infestation treated by pimozide: a double-blind crossover clinical study. Acta Derm Venereol. 1982;62:55-58. 22. Gowda BS, Heebbar S, Sathyanarayana MT. Delusional parasitosis responding to risperidone. Indian J Psychiatry. 2002;44: 382-383. 23. Laidler N. Delusions of parasitosis: a brief review of the literature and pathway for diagnosis and treatment. Dermatol Online J. 2018;24. pii:13030/qt1fh739nx. 24. Elmer KB, George RM, Peterson K. Therapeutic update: use of risperidone for the treatment of monosymptomatic hypochondriacal psychosis. J Am Acad Dermatol. 2000;43:683-686. 25. Freudenmann RW, Sch€ onfeldt-Lecuona C, Lepping P. Primary delusional parasitosis treated with olanzapine. Int Psychogeriatr. 2007;19:1161-1168. 26. Ladizinski B, Busse KL, Bhutani T, Koo JY. Aripiprazole as a viable alternative for treating delusions of parasitosis. J Drugs Dermatol. 2010;9:1531-1532. 27. Duarte C, Choi KM, Li CL. Delusional parasitosis associated with dialysis treated with aripiprazole. [in Portuguese] Acta Med Port. 2011;24:457-462. 28. Kumbier E, H€ oppner J. The neuroleptic treatment of delusional parasitosis: first experiences with aripiprazole. [in German] Hautarzt. 2008;59:728-730, 732-733. €kkarapınar M, Cos¸ar B. 29. Altın€ oz AE, Tosun Altın€ oz S¸, K€ uc¸u Paliperidone: another treatment option for delusional parasitosis. Australas Psychiatry. 2014;22:576-578. 30. De Berardis D, Serroni N, Marini S, et al. Successful ziprasidone monotherapy in a case of delusional parasitosis: a one-year followup. Case Rep Psychiatry. 2013;2013:913248. 31. Milia A, Mascia MG, Pilia G, et al. Efficacy and safety of quetiapine treatment for delusional parasitosis: experience in an elderly patient. Clin Neuropharmacol. 2008;31:310-312.

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32. Cupina D, Boulton M. Secondary delusional parasitosis treated successfully with a combination of clozapine and citalopram. Psychosomatics. 2012;53:301-302. 33. Roulet T, Zdanowicz N. Delusional parasitosis treated by atypical antipsychotic and selective serotonin reuptake inhibitor: a case report. Psychiatr Danub. 2017;29(suppl 3): 219-221. 34. M€ oller HJ, Riedel M, J€ager M, et al. Short-term treatment with risperidone or haloperidol in first-episode schizophrenia: 8week results of a randomized controlled trial within the German Research Network on Schizophrenia. Int J Neuropsychopharmacol. 2008;11:985-997. 35. Thomson SR, Chogtu B, Bhattacharjee D, Agarwal S. Extrapyramidal symptoms probably related to risperidone treatment: a case series. Ann Neurosci. 2017;24:155-163. 36. Woerner MG, Alvir JMJ, Saltz BL, et al. Prospective study of tardive dyskinesia in the elderly: rates and risk factors. Am J Psychiatry. 1998;155:1521-1528. 37. Saltz BL, Robinson DG, Woerner MG. Recognizing and managing antipsychotic drug treatment side effects in the elderly. Prim Care Companion J Clin Psychiatry. 2004;6(suppl 2):14-19. 38. Adler L, Angrist B, Peselow E, et al. Noradrenergic mechanisms in akathisia: treatment with propranolol and clonidine. Psychopharmacol Bull. 1987;23:21-25. 39. Wykoff RF. Delusions of parasitosis: a review. Rev Infect Dis. 1987;9:433-437. 40. Risperdal (risperidone) [package insert]. Titusville, NJ: Janssen Pharmaceuticals Inc; 2017. 41. Orap (pimozide) [package insert]. Sellersville, PA: Teva Pharmaceuticals; 2014. 42. Aripiprazole Orally Disintegrating Tablets [package insert]. Bridgewater, NJ: Alembic Pharmaceuticals; 2017. 43. Zyprexa (olanzapine) [package insert]. Indianapolis, IN: Lilly USA LLC; 2018.